Pressure-operated switch



Flatt.

Dec. 22 ,1925- 4Patented Dec. 22, 1925.

UNITED STATES PATENT OFFICE.

ALBERT S. BERTNZETTI AND SILVIO DE PB ANPERO, ,OF FREDERICKTOWN, PENN- SYLVANIA; SAID DE PRANPERO ASSIGNOR TO SAID BERTANZETTL` PRESSURE-OPERATED SWITCH.

Application filed December 4, 1922. Serial No. 604,967.

To all whom it may concern.

Be it known that we, ALBERT S. BERTAN- zrzr'ri: and SrLvIo DE PRANrnRo, residing at Fredericktown, in the county ofWashington and State of Pennsylvania, citizens of the United States, have invented or discovered certain new and useful Improvements in Pressure-Operated Switches, of which im? provements the following is a specification.

Our invention relates to pressureQoperated switches. It finds immediate use in the lubricating system for the engine of an automobile, and in that use we shall show and describe it; but manifestly it is useful, wherever lubricating oil is circulated` under forced feed, whether in an automobile or elsewhere. It there constitutes an essential element of a precautionary or safety a pliance, to save the car or other machine rom injury pnder conditions which arise in service.

In the accompanying drawings, Fig. I is a diagrammatic view of a circulating system for lubricating oil applied to the crank case of an automobile, to which system our invention is here shown to be applied; Fig. II is a view in vertical section and to larger scale of the pressure-operated switch in which our invention centers.

Referring to Fig. I, the crank case of an automobile is indicated in fragmentary manner at 1. From the bottom ofc the crank case l an oil pipe 2 leads, and returns in circuit and opens again vwithin the crank case, but at such particular place as to eii'ect the de- `sired lubrication o the contained bearings. In the line of circulation pipe 2 is arranged a pump 3, and the usual indicator 4 may communicate with pipe 2. All these features are in common and general use, and no more minute description of them is required.

At a suitable point ina horizontal reach of circulation pipe 2 and on the delivery side of pump 3 is introduced the attachment 5 in which our invention centers.

This attachment consists essentially of a cylindrical chamber, to which in Fig. II the reference vnumeral 5 is particularly applied,

rising vertically from a horizontal reach of 50 circulation pipe 2, and with the circulation pipe the c lindrical chamber is in communication. ommunication is, however, controlled by a downwardly closing check valve, conveniently formed as a spherical valve 10.

ways complete between Within the cylinder a piston 6 is reciprotheir inner ends are preferably made conical in shape, and the piston 6 is preferably made correspondingly conical. Furthermore, to the piston is preferably attached a centrally supported Vplate 9, capable of slight tipping,

and upon thisrplate particularly the conical l configuration ma be imposed. The piston 6 with its end ate 9`are formed of conducting materia brass or other metal; the cylinder is likewise formed ordinarily of brass, and electrical contact is always maintained between cylinder and piston, and, when the piston descends to the permissible limit, between piston and contact pieces. But the contact pieces alwa s are insulated from the conducting materia of the cylinder wall which sustains them. The tipping plate 9 upon piston 6 is provided, to insure electrical contact with both contact ieces on descent of the piston to the ermlssible limit.

We have said that e ectrical contact is alv iston and cylinder. This 1s ensured by re ucing the cylinder bore above and causing the piston stem tobe closely engaged thereby. The contact is ermeable by air, as the piston risesy and fal s..

The cylinder. 5 is open above, and its bore 1s enlarged slightly at the upper end, as indicated at 11. We find that by resort to this slight enlargement in the bore of the piston, leakage of oil is effectively prevented. l

To one contact piece 7 is connected a lamp circuit 12, or a circuit containing a tell-tale device ofsome other form; to the other is connected a circuit 13 which, being ,energized, makes ineffective the sparking device or other electrical control of the engine.

Operation will readily be understood. ySo long as oil is circulating under pressure through circulation pipes 2, piston 6 will be -held elevated, circuits 12 and 13 will be uncompleted and ineliective. If oil fails, the pump continuing in operation, air accumulating in cylinder 5 will escape, yfailing to hold the piston elevated. The piston will descend, the two electrical contacts will be closed, both circuits 12 and 13 will be grounded through cylinder 5, the light or equivalent tell-tale will function, and, the spark failing, the engine will stop. Again, if water accumulates in the crank case it will be circulated, and, collecting, in the cylinder 5, will short circuit the terminals of the two circuits 12 and 13, establishing electrical contact between the terminals 7, and the practical effect will be the same as before. Indeed, it may be kremarked that with both circuits each grounds the other when the piston engages both contact pieces, or when water accumulates between the contact pieces.

Thus, whether oil fails or water accumulates, the driver of the car will have advice and his engine will stop.

1n the practice of the invention the structure may include either or liiioth the circuits 12 and 13, as may be desired.

lt remains only to note that when under normal operating conditions the engine is stopped, and with it the pump 3, the valve 10 is eective to retain within cylinder 5 the body of oil there normally accumulated. So while the automobile remains standing the circuits 12 and 13 remain ungrounded (and it is circuit 13 which is of particular importance here). rllhe spark apparatus will continue in active condition when the engine is to be started again.

Manifestly the invention is applicable generally to engine installations, but we have described it in application to an autov mobile engine specifically, for inthat application We have developed it.

We claim as our invention:

ln an oil circulating system for .a gas engine, a circulation pipe, a pressure chamber in communication with said circulation pipe, a contact piece adapted to be held inactive under accumulated pressure within the chamber against an opposing force, and a check valve controlling the communication between circulation pipe and pressure chamber.

ln testimony whereof we have hereunto set our hands.

ALBERT S. BERTANZETTL SUIVI@ DE PRANPERU. 

